在网格视图中从40个图像中随机显示25个图像 [英] To show 25 images randomly out of 40 images in a grid view

问题描述

我正在创建一个iphone应用，我需要在其中创建25个图像的网格视图。
我这样做是通过在一个数组中拍摄25张图像，并通过使用for循环显示它们，方法是在下面的代码中更改x轴和y轴的尺寸：

I am creating an iphone app in which I need to create a grid view of 25 images. I am doing that by taking 25 images in an array, and displaying them by using for loop by changing the dimensions for x axis and y axis in below code:

for(int i=0; i<25; i++)
    {
    if(i>0)
    {
        if(i%5==0)
        {
            xaxis=30;
            yaxis=yaxis+35;
        }
    }
        iconButton[i]=[UIButton buttonWithType:UIButtonTypeRoundedRect];
        iconButton[i].frame=CGRectMake(xaxis, yaxis, 50, 30);
        [iconButton[i] setBackgroundImage:[iconArray objectAtIndex:i] forState:UIControlStateNormal];
        [iconButton[i] addTarget:self action:@selector(changeImage:) forControlEvents:UIControlEventTouchUpInside];
        [self.view addSubview:iconButton[i]];
        xaxis=xaxis+55;
    }

它工作正常，但我和我共有40张图片，我每次都想要当应用程序启动时，它应该从25张图像中随机选取25张图像。

It working fine but I have total 40 images with me and I want every time when application will launch it should pick the 25 images randomly out of that 25 images.

我如何做到这一点，请帮助我。

How will I do that, please help me.

非常感谢您的帮助。
问候
iPhoneDeveloper11

Many Thanks in advance for your help. Regards iPhoneDeveloper11

推荐答案

创建一个包含41个数字（0-40）的数组，使用它们随机播放部分 Fisher-Yates shuffle
并使用数组的前25个元素。

Create an array of 41 numbers (0-40), shuffle them using a partial Fisher-Yates shuffle and use the first 25 elements of the array.

伪代码（random（x）返回0到x之间的随机数）：

Pseudo-code (random(x) returns a random number from 0 to x inclusive):

array = [0, 1, 2, ..., 40]
for i in 0, 1, ..., 24 do
    swap array[i], array[i + random(40 - i)]
truncate array to 25 elements.

这篇关于在网格视图中从40个图像中随机显示25个图像的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！